Crash when exiting Hag's End

[PandaPo]

I returned to Hag's End to find the Assassin of Old, a minor quest from the DB questline. I had previously cleared it a long time ago in the course of game play.
After finding said Assassin and clearing all of Hag's End I get a consistent CTD when exiting to Deepwood Vale. I am unsure what is causing this. Both exits are affected; the one where one normally enters and the other after the word wall.
Any ideas? I will try to COC out but if that doesn't work...

Nope, COC also results in a CTD.

Hmmm. Loading the save from when I entered, and exiting immediately, also resulted in a CTD